(A) Field of the Invention
This invention relates to storm shutters adapted to protect glass windows, doors and similar openings in buildings against damage from wind forces and wind driven debris.
(B) Discussion of Related Art
Storm shutters intended to protect glass windows, doors and similar openings in buildings against high velocity winds and wind driven debris have been recently developed for use in coastal and other areas subjected to meteorological disturbances such as hurricanes, tornados and similar events that expose building structures to high velocity winds and debris driven by such winds.
It is highly desirable to protect such glass covered openings against breakage to minimize damage to the interior of the building that would otherwise occur as a result of wind generated internal pressures within the structure and wind driven rain.
More recently, local governments have enacted regulations governing the building of structures in hurricane prone geographic areas mandating that various building components, including shutters, meet minimum specifications governing strength, impact resistance, shatter resistance and load bearing ability. Storm shutter, like other building components subject to such mandates, must be capable of meeting such specifications while at the same time preserving structural features that enhance the commercial marketability of such shutters.
It is important that such shutter system be relatively light weight and easy to handle by a homeowner or business proprietor; be resistant to deterioration from outside weather, including sunlight; and be easily installed and removed over the useful life of the shutter.
One form of shutter that has enjoyed commercial acceptance is illustrated in U.S. Pat. No. 4,333,271 granted Jun. 8, 1982. In accordance with the shutter system described in the patent, corrugated panels of metal are retained on the outside of a building opening such as a glass window or doorway by a sill member extending along the bottom of the shutter and a channel-like header unit that receives the upper ends of the panels. Installation of such a shutter is simply a matter of sliding individual corrugated panels upwardly into the header and fastening them at their bottom ends to the sill area. The corrugated panels nest together along adjacent corrugations to provide a structural panel capable of resisting winds and wind driven debris that would otherwise impact a window or door protected by the shutter.
A problem with this type of shutter, of course, is that, once installed, passage of light through the window or door is blocked. The interior of the building is rendered dark and, in the event of a power failure that often occurs during meteorological disturbances, the interior of the building becomes dark and inhospitable. Also, the opaque storm shutter prevents occupants from observing their surroundings outside the building which raises the anxiety level of the building occupants before, during and after a disturbance.
Prior art attempts have been made to make such a storm shutter transparent to enable viewing through a door or window to be protected and such an example is described in U.S. Pat. No. 5,457,921 granted Oct. 17, 1995. This type of shutter is constituted of corrugated transparent plastic panels attached to each other and to the framework of a window or other opening to be protected. However, it has been observed that such shutters also have disadvantages due to the large expanses of synthetic resin panels utilized and the manufacturing cost of producing corrugated sheets of impact resistant, weather resistant transparent plastic that is sufficiently rigid to meet all specifications applicable to storm shutters.
Other storm shutter systems are described in the following patents:
______________________________________ Pat. No. Issue Date 4,685,261 August 11, 1987 5,228,238 July 20, 1993 5,345,716 September 13, 1994 5,383,315 January 24, 1995 5,426,893 June 27, 1995 ______________________________________